Four functions, F1, F2, F3 and F4, are registered to the net…

Four functions, F1, F2, F3 and F4, are registered to the netfilter hooks. F1 is registered to NF_INET_POST_ROUTING with a priority -130. F2 is registered to NF_INET_POST_ROUTING with a priority -120. F3 is registered to NF_INET_LOCAL_OUT with a priority -110. F4 is registered to NF_INET_FORWARD with a priority -100. When a firewall receives and allows an ICMP echo request packet from an internal host, in which order, the functions will be invoked? (In case an entire correct order is not presented, choose one with the correct partial order)